Rope



Sept. 1s, 1945.

E. H. WHITE 2,385,241

RQPE

` Filed sept. A27,' 1945 2 sheets-sheet 1 E. H. WHITE Sep@ 18, 1945.

ROPE

2 Sheets-Sheet 2 Patented Sept. 18, 1945 ROPE Edward Horace White,Warrington, England, as-

signor to The Whitecross Company Limited, Warrington, EnglandApplication September 27, 1943, Serial No. 503,998 In Great BritainSeptember 18, 1942 1 Claim.

This invention relates to the manufacture of ropes and the like, andmore especially to the construction of the locked coil wire ropes suolias used for colliery winding gear, sinking, or other ropes built on theconcentric or multiple strandv pattern, more particularly of thenonrotating type. More particularly it relates to the method andapparatus of Patent No. 1,992,707,

according' to which the tendency of the core to locked coil wires or thelike placed upon it whilst avoiding untwisting of the outer coveringlayer of the wires or the like after they have been laid upon the core.

In winding, and other ropes, made by the process referred to, successfulresults have been obtained in all cases, but in connection with thelargest diameter of winding` ropes made of locked coil construction, itis found `that if the users do not re-set the ropes carefully to allowthe selftightening properties to operate in a manner which would take upthe, stretch in the outer wires, the outer covering may become loose onthe core, and unevenness develop in waves, due to the slipping of theouter covering wires on the core, and consequent local overcrowding.. y

The object of the present` invention is to, provide for the overcomingof this diiiiculty, in-the case of non-twistingropes, ,especially thoseaccording to United StatesPatent N o. 1,992,707.`

After much experiment it has been found that this can be eiiectedbymeans of a supplementary layer in the outervcovering of the rope, andthat it is particularly applicable to the case of large ropes, that isto say, ropes from 4a diameter of one and five eighthsor one and three'quarter inches upwards, the extra layer being' laid in a direction, thatis to say tov a hand, similarto that of the outer layer of the cover andopposite to the hand orlay of thel layers of wires constituting thecore. Several results arise from this mod,- ication of the method: ofmaking ropes, one of which is that the re-setting of the rope from theend' at which the load is attached isonly required at comparatively longintervals', for instanceV at each re-capping, which has byustatute totake place at intervals of not more than six months,

the rope will automatically re-set itself if allowed to do so, and thestretch in the outer wires will be automatially taken up and the outerlayers remain tight.

' Another valuable property in the new improved construction is thatwire ropes of either right or left hand outer layers can be used on awinding drum which is arranged either right or left hand, whereas withother forms of locked coil or contra-lock windingropes, it is necessaryfor the rope to be designed with the outer layer either right or lefthand to suit the particular lay-out, i. e. when looking towards theshaft from the opposite side of the drum, if the under-rope winds on,commencing at the right `on the drum and coiling towards the left, arope of right hand lay must be usedcompare British Safety in MinesResearch Board Paper, No. 41, Chapter XI, which reads: In certain casesthe rope should be right hand or left hand lay, according to thedirection inv which it coils on the drum; that is', when looking towardsthe shaft, from the opposite side of the drum, if the under rope windson commencing on the right and coiling towards the left, a rope with aright hand lay should be used. This will give the rope a tendency totighten up during use; if a left hand lay is used the tendency will beto untwis The outer covering of ropes according to the present inventionmay :be taken as comprising. two layers, namely, the outermost layer,and an additional or supplementary layer between the outermost layer andthe core.

l The outermost layer should be of full-lock construction, but thesupplementary layer which is laid to the same hand as the outer layermay be of full-lock, half-lock or segmental sections, or even a simplecircular section.

This double outer layer of section wires is not simply a duplicationfrom the aspect of using two layers instead of one, but it has afunctional effect:

Firstly, from the fact that two layers in a concentric cable laid up inthe same direction have a much greater area of contact than in the caseof crossed layers, and therefore the outer layer is not inclined toslide upon the inner layer. l

This is illustrated in a diagram referred to below, and is borne out inpractice by the fact that the outermost layer has a strong grippingeifect on the second layer, so much so that even when the usual endclamps or servings are removed there is very little tendency to slip orspring apart.

Secondly, with the two outer layers of wires The invention consists in anon-twisting rope consisting of a core comprising a number of layers ofwire wound to one hand, two layers of wires disposed around this core,these layers both being laid to the same hand but to the opposite handfrom that of the core, and in which there is a twist in all the layersof the core with respect to the rst or inner layer of the two coveringlayers, the sectional areas of the core layers multiplied by theirrespective distances from the centre being not less than the sectionalarea of the two outer layers multiplied by their respective distancesfrom the central axis of the rope.

Referring to the accompanying diagrammatic drawings:

Figure 1 is an end elevation, and

Figure 2 a side elevation, with parts of the various layers removed, toillustrate one form of the present invention:

Figures 3 and 4 are views similar to Figures 1 and 2, but of a modiedform of the present invention: f

Figures 5 and 6 are diagrams to assist in eX- plaining untwistingtendencies or resultant torque due to the load acting on the variouslayers of a rope.

Referring to Figures 1 and 2, the core consists of the parts of the ropemarked a, comprising a number of layers otwires of circular or what maybe termed of rail section, with voids or filled intersticesy indicatedby b. The outermost layer indicated by e is formed of wires of full-locksection, laid to a hand opposite from that of the core. Between thisoutermost layer e and the core a, a supplementary cover layer f isdisposed, wound to a hand opposite from that in which the core wires aand the outermost covering wires e are wound. The part broken away fromFigure 2 from the wires of the outermost covering e shows, that there isa very large area of contact between the wires e and the. wires f, whichin practice results in a strong gripping effect, as referred to above. t

, In the form of the invention shown in Figures 3 and 4, the core wiresa are similar to those in Figures 1 and 2, and the same applies to thewires e constituting the outermost layer of the cover. The supplementarylayer of the cover ishere formed bywirestgwhich are of circular section,but as in Figures 1 and 2, the wires a and e are wound to oppositehands, whereas the wirese and g are wound to the same hand. It is,however, preferred to use non-circular wires for the supplementary layerof the cover, in accordance with Figures 3 and 4, rather than wires ofcircular cross section, as illustrated in Figures 3 and 4, for circularcross section wires may tend to have a certain amount of cutting eiect.v

Wire ropes according to Figures 1 and 2 or3 and 4 may conveniently bemade by means of apparatus as described in United States Patent No.1,992,707, or in either of British Specifications Nos. 388788 or 493077.

Referring now to Figures 5 and 6, a measure of untwisting tendency, orresultant torque due to the load acting on the various layers of therope may be obtained from the sectional area of each layer multiplied bythe distance of its centre-line from the central axis of the rope.

Referring to the diagram Figure 5 showing the outside of a concentricrope or strand, in which the Wires are laid at an angle a to AC, thecentral axis, if it be imagined that one wire be taken and rolled offinto a plane for the length of one complete lay, then in Figure 6 thisis represented by CB, W representing the load acting along the centralaxis, T representing the tension in the wires due to this load at anangle of lay a.

The closing resultant of the triangle of force is represented by ABacting at right angles to the central axis.

From the simple triangle of forces, the torque: load multiplied bytangent of angle of lay (from diagram AB=W tan a) and this, divided overthe layers of the rope according to their sectional area multiplied bythe distance of the centre-line of each layer from the central axis ofthe rope, would enable the calculation to `be made as to the relativebalance between the two outer layers laid one hand, and the core layerslaid to the other hand.

Assuming the sectional area` of the various core layers, starting fromthe centre of the rope to be Al, A2, A3, and so on, acting at distancesRI, R2, R3, and so on from the central axis of the rope, and thesectional area of the two outer layers to be AO.I and AO.2 respectively,acting at distances of ROJ'and RO.2 from the central axis of the rope,then in general the design of rope should be such that whatever thesections used in the various layers, the torque resulting from thesectional areas of the core layers multiplied by their respectivedistances from the centre, should not be less than the torque resultingfrom the sectional area of the two outer layers multiplied by theirrespective distances from the central -axis of the rope,V i. e.,

(AI XRD-l-(AZXRZ) +(An Rn) The over-balancing eiect which keeps theouter layers tight will then be provided by the overtwistput into thecore, the amount of which is capable of calculation, and easilyascertained by trial, as is mentioned in the patent specificationreferred to above.

The computation just given assumes that the angle of lay is constantthroughout and some small adjustment is required where a wide variationoccurs between the angles of lay inldiierent layers. i -General Thepresent invention is best applied to those cases Where the outer layeris of full-lock construction only, and to ropes of one and five eighthsinches diameter and larger, in which the total sectional area of thewires of the two outer layers which is required for practicalV workingconditions can be so designed that the untwisting moment of thesetwolayers remains less than the untwisting moment of the core, plus overdtwist, that is, plus the additional untwisting moment due to theovertwist which is put in to the core, whilst the supplementary layer tothe opposite hand is laid around it. The overtwist is put into the corewhilst the supplementary layer is being laid round it. The outermostlayer of full-lock Wires is then laid on.

In ropes of a smaller diameter than one and ve eighths inches thesectional area of the wires of the outer layers may have to be soreduced in order to give effect to this requirement that they would notbe heavy enough to provide the necessary wearing surface, and in anycase the necessity for special treatment in the construction of ropes ofless than one and ve eighths inches diameter does not arise, to such animportant degree.

A property observed in ropes made by the new modified consruction isthat a straight rope may be obtained, with no tendency to curl at anypart of its length, whereas in new ropes of either the originalcontra-lock of other locked coil constructions, a set or curl can beobserved when the rope is cut at any point, or released from tensionafter pulling off from its reel. This apparently means that the internalstresses in the complete structure under the modied construction areeither absent, or more perfectly balanced than with the otherconstructions referred to, in which the set or curl indicates someunreleased stresses remaining, and in addition this property renders theropes easier to handle through slightly greater flexibility and freedomfrom tendency to kink.

I claim:

A non-twisting rope consisting of a core comprising a number of layersof wire wound to one hand, two layers of wires disposed around thiscore, these layers both being laid to the same hand but to the oppositehand from that of the core, and in which there is a twist in all thelayers of the core with respect to the rst or inner layer of the twocovering layers, the sectional areas of the core layers multiplied bytheir respective distances from the centre being not less than thesectional area of the two outer layers multiplied by their respectivedistances from the central axis of the rope.

EDWARD HORACE WHITE.

